Has anyone ever removed the vent caps and cleaned the vent pipes for the holding tanks?

I was going to remove the vent caps on top of camper roof for the holding tanks and flush them out with a bleach soloution and garden hose. Do you think this will harm anything?

Also I started to remove the vent cap for the grey water tank and it started to crack so I left it alone. It says "pull to reomve" right on top of the vent but it does not want to just pop off. Is there an easier way to get the vent cap off?

Never in all my RV ownership or home ownership for that matter has there ever been a need to clean the vent lines. They are just that, a vent, air flows through them. Why do you think they need cleaning?

the tank was over filled when we got the camper and the seweage was up to the toilet, so it would make sense that the sewege was also up in the vent line. there is a smell, not a bad smell and i was thinking the vent line may contain some stuff.

There is a small screw(or two) that secure the cap. At least it was that way on my trailers. They're easy to miss because they have caulking over the screw head.
The vent pipes can get clogged. Wasp & mud daubers can build nest on the inner wall of the piping and prevent proper draining of the tanks.

There is a small screw(or two) that secure the cap. At least it was that way on my trailers. They're easy to miss because they have caulking over the screw head.
The vent pipes can get clogged. Wasp & mud daubers can build nest on the inner wall of the piping and prevent proper draining of the tanks.

The one on the left make me Dizzy.

Thank you for the info about the sealant, I will remove the sealant and look for the screw.